The Jean Carles method

Carles opens with a view of the trade: most of his own teachers worked by trial and error, adding a little at a time with no plan. He held that a learner needs a framework. He also held that there is no special inborn nose; what sets a perfumer apart is olfactory memory, and that memory comes from practice.

The first step is to smell every material, natural and synthetic, in a deliberate order. The learner first smells strongly contrasting odours, to separate the large groups. Only then come materials within one family, where differences are smaller and harder. Carles describes his perfumers testing their knowledge of materials every day.

Smelling strips repeatedly, the learner soon notices that odour changes over time and that each material evaporates at its own rate. Carles turned that observation into an exercise. On each strip, write the date and time the drop was applied, then the date and time the material begins to lose its characteristic odour. Later off-notes are ignored.

He stresses that such a table could be drawn up scientifically, but that the learner progresses faster by building his own. The result sorts every material into three groups. The very volatile, short-lived group is the top notes; citrus oils such as lemon and bergamot belong here. The group of intermediate volatility and tenacity he called modifiers, including many floral materials such as neroli and ylang-ylang. The slow, highly tenacious group is the base notes, such as oakmoss, patchouli and vetiver.

The word modifier was chosen for a reason. According to Carles, many base materials smell unpleasant just after they are put on the strip, and only become attractive in later stages. The middle group's job is to soften that first impression. Top notes give a pleasant effect on opening the bottle, but he warns that the top note is never the main character of a perfume; that character lies in the base.

Carles called a small blend of materials with a unified impression an accord. His method starts at the base. Choose the base material that will set the character, then a second base material that suits it. Blend the two in a series of gradually shifting proportions, smell each, and keep the one in which the main material still leads. Once the second material takes over, the accord has become a different idea and is no longer the one being sought.

The base accord can be extended with a third and fourth material, giving each one a turn at dominance to see which way it pulls the character. Once the base accord is settled, the learner chooses modifiers to soften the harsh opening of the base, and only then builds the top-note accord, where Carles allowed much more freedom. The balance between the three groups largely decides how long the perfume lasts: too little base relative to middle and top, and the scent will not hold.

The worked example in the article is a chypre accord built around oakmoss, with an amber-type base material and a musk, then a rose note as modifier, and sweet orange with bergamot on top. Some ingredients in the example are Roure house bases, known by internal code numbers, whose formulas are not public.

The systems from Linnaeus to Henning ask how odours resemble one another. Carles asks how materials behave over time. That is why the top, middle and base division remains in wide use though it is not a theory of smell: it describes something observable on the strip and on skin, and it helps a compounder foresee how a scent will change. Because volatility also depends on concentration and carrier, Carles asked each learner to build a personal table rather than memorise his.